Chemistry (Weinh.) Chemistry (Weinh.) Cu‐Ln (Ln = Gd, Eu, Sm) Dinuclear Complexes Based on Schiff Base <i>o‐van‐en</i> Ligand: Syntheses, Crystal Structures, and Magnetic Properties Košcíková Andrea Cernák Juraj Falvello Larry R. Tomás Milagros Ara Irene Universidad de Zaragoza Titiš Ján Boca Roman 2025 research-article